If your baby is 5.0 kg at three months and the WHO median says 6.4 kg, the first thing to know is this: the median is not the target. Anything between the 3rd and 97th percentile is normal, and a baby who was born at 2.6 kg is simply not going to weigh the same as one born at 3.6 kg.

Check where your baby actually sits before you change anything — plot the number on the free Baby Growth Chart tool, and read the full 3 month baby weight chart in kg.

First: is the weight actually low?

Low weight is a pattern, not a number. Only these count as genuine concerns:

• Weight has crossed two percentile lines downwards (e.g. 50th → 15th)
• The baby has not gained for 2 consecutive weeks
• Weight is below the 3rd percentile on the WHO/IAP chart
• Fewer than 6 heavy wet nappies in 24 hours
• Baby is lethargic, hard to rouse, or feeds for under 5 minutes and gives up

If none of these apply, your baby is small — not underweight — and no intervention is needed.

Expected gain at this age

| Age | Expected weekly gain | Monthly gain |

| --- | --- | --- |

| 0–3 months | 150–200 g | 600–900 g |

| 3–6 months | 100–150 g | 450–600 g |

| 6–12 months | 70–90 g | 300–400 g |

Gain naturally slows after month three. A drop from 200 g to 140 g a week at 13 weeks is normal, not a problem.

The only things that safely increase weight at 3 months

At 3 months, the answer is always more effective milk, never food. Solids before 6 months displace calorie-dense milk and are linked to poor gain, not better gain.

1. Fix the latch (the single biggest lever)

A shallow latch means the baby works hard, tires early and gets the watery foremilk without draining the fattier hindmilk. Signs: clicking sounds, nipple pain, flattened nipple after feeds, feeds over 45 minutes, baby falling asleep at the breast within 5 minutes. One session with a lactation consultant fixes most of it — see our lactation consultation.

2. Increase feed frequency, not feed length

Aim for 8–12 feeds in 24 hours, including 1–2 night feeds. Waking a sleepy baby for a feed during the day is appropriate when weight gain is slow.

3. Finish one breast before switching

Draining one side fully gives the baby the calorie-dense hindmilk. Switching sides every 5 minutes gives two servings of foremilk and a hungry baby an hour later.

4. Breast compressions

Gently compress the breast while the baby sucks but is not swallowing. This pushes more milk through and keeps a sleepy baby actively feeding.

5. Skin-to-skin, daily

Kangaroo care reliably improves feeding efficiency, sleep and weight gain — it is the most evidence-backed "free" intervention available.

6. Treat the mother, not just the baby

Low supply usually traces back to infrequent feeding, pain, mastitis, retained placenta, thyroid issues or severe anaemia — all common postnatally in India and all treatable. Eat 400–500 extra kcal a day, hydrate, and get haemoglobin and thyroid checked if gain is stuck.

7. Maalish, done right

Daily oil massage (coconut, sesame or mustard) has Indian clinical data behind it for improved weight gain in infants, likely through better sleep and lower stress hormones. Warm oil, gentle strokes, 10–15 minutes, not immediately after a feed.

8. Rule out silent causes

Tongue tie, reflux, cow's milk protein allergy, recurrent infections, anaemia and undiagnosed heart or thyroid conditions all present as poor weight gain in an otherwise "fine looking" baby. Ask your paediatrician to check.

What NOT to give a 3-month-old

These are widely suggested in Indian families and are all unsafe before 6 months:

• Cow's or buffalo milk — protein and mineral load an infant kidney cannot handle; risks anaemia and intestinal bleeding
• Ghutti, gripe water, janam ghutti — no calories, risk of contamination
• Sugar water, honey, glucose — honey carries infant botulism risk under 1 year
• Rice water, dal ka paani, mashed banana, cerelac — displaces milk calories and increases infection risk
• Ragi or sattu porridge — excellent later, wrong before 6 months
• Random weight-gain tonics — unregulated and unnecessary

If you are formula feeding

Never over-concentrate the formula to "add calories" — it dehydrates the baby and strains the kidneys. Follow the tin's scoop ratio exactly. A 3-month-old typically takes 150 ml per kg of body weight per 24 hours, split across 6–8 feeds. Paced bottle feeding reduces the swallowed air that cuts feeds short.

A realistic 2-week plan

Days 1–2: log every feed, its length and every wet nappy

Day 2: book a lactation review if there is any pain, clicking or short feeds

Days 3–14: 8–12 feeds daily, one breast fully drained per feed, compressions, daily skin-to-skin and maalish

Day 7 and Day 14: weigh on the same scale, same time of day, undressed

Take the log to your paediatrician if gain is under 100 g a week

When to see a doctor now, not next week

Fever of 100.4°F or above under 3 months, fewer than 6 wet nappies a day, a sunken soft spot, vomiting that is green or projectile, blood in stool, breathing difficulty or sweating during feeds, extreme floppiness, or any actual weight loss.

Track it properly

Plot each weigh-in on the free Baby Growth Chart tool so you can see the curve rather than a scary single number, and read the 3 month baby weight chart in kg for boys and girls for the full percentile table.